According to a new study published in Clinical Infectious Diseases, taking antibiotics for diarrhea may put travelers visiting developing parts of the world at higher risk for contracting superbugs and spreading these drug-resistant bacteria to their home countries. The study authors call for greater caution in using antibiotics for travelers' diarrhea, except in severe cases, as part of broader efforts to fight the growing public health crisis of antibiotic resistance and the spread of highly resistant bacteria worldwide.
In the study, researchers collected stool samples for testing from 430 Finns before and after they travelled outside of Scandinavia. The goal: Determine if their guts became colonized by a resistant type of bacteria from the Enterobacteriaceae family that produces a key enzyme, extended-spectrum beta-lactamase (ESBL), which confers resistance to many commonly used antibiotics. The researchers looked for risk factors in the travelers' behavior that may have facilitated colonization by these resistant bacteria, which can cause severe infections that are harder and more expensive to treat and more likely to be fatal.
The Finnish travelers completed surveys about their trips, including questions about diarrhea and antibiotic use, which can disrupt the gut's balanced ecosystem, sometimes allowing resistant bacteria to become incorporated into the intestinal ecosystem.
Overall, 21 percent of the travelers to tropical and subtropical areas in the study had unknowingly contracted ESBL-producing bacteria during their trips. Significant risk factors for colonization were travelers' diarrhea and treating it with antibiotics while abroad. Among those who took antibiotics for diarrhea, 37 percent were colonized. Those travelling to South Asia faced the highest risk of contracting the resistant bacteria: 80 percent of travelers who took antibiotics for diarrhea while visiting the region were colonized with ESBL bacteria. Southeast Asia, East Asia, and North Africa together with the Middle East, in order, were next highest in risk.Read the article on the Clinical Infectious Diseases website